Mounting for lift truck platforms



June 3, 1941. G. QUAYLE Y MOUNTING FOR LIFT TRUCK PLATFORMS Filed July 25, 1940 2 Sheets-Sheet 1 l l l t Llll y IW

INVENTOR ATTORNEY June 3, 1941. G. QUAYLE MOUNTIANG FOR LIFT TRUCK PLATFORMS Filed July l25, 1940 2 Sheets-Sheet 2 INVENTOR Patented June 3, 1941 U N I T ED STATE S PATENT GFFIC MOUNTING FOR/.LIFT TRUCK PLATFORMS George QuayIaPhIadelphia Pa.,.assgnor toThe Yale & Towne Manufacturing Company, Stamford, Con-n., a corporation of Connecticut.

Application July '25, '1940, Serial No.. 347,467

13 Claims.

This invention relates to a lift truck' and particularly means for supporting the upwardly movable lifting platform of aV lift, truck. More particularly, my inventionf relates to linkage means for mounting the elevating platform or a lift truck relatively to the mainframe of thesaid lift truck whereby through pivotal motion, the platform will be elevated.

Broadly, such linkage mechanism as I havedevised is vold and well known in the art, my construction varying from theprior art inits: simplicity of design and assembly, and in its` exceeding strength.

Also, as a feature of. my invention, I mount the platform of my lift truck relatively to the main frame through linkage which is independent of the rear Wheel mounting of. the truck, thereby facilitating the utilization of wheels` of varying sizes` without necessarily varying the linkage connection between the platform and the main frame, as is now required.

Asa further feature of my invention, my linkage mechanism, and the meansv whereby itv is connected to the elevating` platform, comprise preferably a single unit supported by bearing means relatively to the platform ink a manner which facilitates assembly. Even more particularly, my linkage vassembly comprises a bearing shaft on which are placed endwise movableV bearing members which are then securedl iny spaced relation to the elevating platform. It is through these spaced bearing members that the platform bears against the shaft and the link assembly.

As a further feature of my invention, I arrange for a` simple reinforcing means for my linkage mechanism. Moreover, as-a further feature of my invention, I utilize this reinforcing means, which is preferably in the form of a tube extending between the links, for housing a supporting shaft for the links, the links being formed with bearing openings in which the supporting shaft rests, and the said bearing openings being preferably in communication with thebore of the tube whereby lubricating material within the tube is always available to said shaft.

I have thus described my invention somewhat generally in order that the construction thereof may be readily understood. It will, of course, be appreciated that there are further features of the invention which have not so far been set forth, but which will be described. in the specication which follows and included in the claims. Moreover, the contribution of my. invention'may readily be embodiedin varying physicall forms by those skilled in the art, and I therefore expect Cil 1 ing` handle. I3.

toobtain` a monopoly which will prevent the appropriation of my: invention through the use of such other forms. r

Referring now to the drawings, Fig. 1 is a side elevation of a lifttruck in which one form of my invention is incorporated. Fig. 2 is a section taken along lines 2.--2 of Fig. 3, Fig. 3 being a plan view.k and partial section of the rear end of the truck of Fig.. 1. Fig. 4 is a perspective-view of the linkage assembly of my invention. Fig. 5 is a sectional view along lines 5-5 of Fig. 2".

Referring now more particularly to the drawings and especially Fig. 1, reference numeral Iii designates an elevating platform supported atV its front end: in a conventional manner relatively' to a main frame I I, and with the platform, being adapted for elevation by suitable means maintained within a covering member I2 carried by the platform and actuatedrby a lifting and steer- Actually, the lifting mechanism for. the truck of; my invention is shown inmy copending. application Serial No. 274,659, filed May 19, 1939. ItY will, be understood that my invention, to be described shortly, may be utilizedin any type of elevating truck. having a lifting platform adapted for elevating movement relatively to supporting'means.

Referring now especially to Figs. 2, 3 and 4, the elevating platform I Il is shown as supporting through suitable bolts I4 and I5, a pair of spaced bearings I5; These bearings I6 are adapted to be slipped over the ends of what I term a: bearing shaft I'I, the shaft being rotatable relatively to the bearings thereafter. It will be appreciated from a view'of Fig. 3, that when the bearings I6 are secured to the elevating platform IIJ, the bearing shaft II can not be moved endwise relatively to the bearings, and moreover, the `bearings cannot Ibe moved off the `ends of the bearing shaft itself.

Right and left hand lifting links I3 are each welded at their upper ends as at I9 to the bearing shaft Il. Gusset plates 20 are welded at ZI to the links I8, and -at 22 to the bearing shaft I'I, thereby assisting in securing the links to the bearing shaft and in reinforcing the union between' the links and thebearing shaft.

A tube 23 is positioned between the links I 8, and is welded at its ends to the links, as indicated at 2G. In this way, the links I8, the tube 23, and the bearing shaft I7 form a complete unit reinforced as shown by the gussets 26. Eachof the links I8 is shown bored out as at 2liv for the mounting of a bearing bushing 2f. The bored-out portion 25 is soformed that the bearing bushing 25 will at all times be in communication with the inside of the tube 23, all as is apparent from the drawings.

A supporting shaft for the links i8 is designated by reference numeral 2l, and traverses the tube 23 and the bearing bushings 26 of links I8 for mounting preferably in openings formed in side bars Ha of the main frame H. For securing the shaft 2l against rotation, there is welded thereto as at 28 a small plate 29 which is secured through a screw 3% to the side bar lia of the main frame Il, all as is probably best indicated in Figs. 2 and 5.

It will be well to point out at this time that the link supporting shaft 2l is maintained in endwise spaced relation to the main axle 3l, on which are mounted the wheels 32 of my lift truck. Because of this relationship between the parts, it is possible to utilize varying sizes of wheels without in any way changing the relationship between the main and elevating frames, as will be quite apparent to those skilled in the art.

There is secured to the tube 23 in a conventional manner an oil or grease cup 33, through which lubricating material may be inserted into the tube 23 whereby to be maintained available at all times for use within the bushings 26, whereby the pivoting action of the links relatively to the stationary shaft 21 maybe lubricated.

Referring now again to Figs. 2 and 5, it will be noted that both faces of each of the bearing portions I6 are cut away as at Ilia. Actually, it is not required that both faces be cut away except to permit interchangeability of the bearings. It is the purpose of this construction to allow the gusset 22 to move as closely as possible to the bearings i6, whereby to assist in preventing deflection of the main bearing shaft.

Moreover, it will be noted that because the links I8 are placed relatively closer to one another than the points at which the shaft Il -bears on bearings I6, there will be a tendency to spread the links i8 at their upper ends. Those skilled in the art will readily appreciate that this spreading tendence is resisted by tension within the shaft Il, and therefore is quite effectively prevented. Because of this construction, a very rigid linkvassembly is obtained with a minimum of weight.

I now claim:

1. In a truck of the class described, a rear link assembly comprising a bearing shaft, spaced rear links each welded at one end to said bearing shaft, gussets welded between said links and said bearing shaft, a tube welded 'at'its opposite ends to said rear links, and bearing openings in said links formed concentric with said tube.

2. In a truck of the class described, a rear link assembly comprising a bearing shaft, spaced rear links each welded at one end to said bearing shaft, a tube welded at its opposite ends to said rear links, and bearing openings in said link formed to communicate with the opening in said tube.

3. In a truck of the class described, a rear link assembly comprising a bearing shaft, rear links each welded at one end to said bearing shaft at spaced points, a tube positioned between said links and welded to the said links near the opposite ends of said rear links, bearing openings in said links formed to communicate with the opening of said tube, and a supporting shaft for said links traversing the said tube and said bearing openings.

4. In a truck of the class described, a main frame, a lifting platform, a rear link assembly for pivotally connecting said main frame and platform comprising a bearing shaft, bearings on said platform with which said shaft cooperates, rear links welded at their upper ends to said bearing shaft, a tube welded at its opposite ends to the said links near the lower ends thereof, bearing openings in said links formed to communicate with said tube, a shaft traversing the said tube and bearing openings, and means supporting said shaft on said main frame.

5. In a truck of the class described, a main frame, a lifting platform, a rear link assembly for pivotally connecting said main .frame and platform comprising a bearing shaft, circular spaced bearings, on said platform through which said shaft extends, rear links welded at their upper ends to said bearing shaft, a tube welded at its opposite ends to the said links near the lower ends thereof, bearing openings in said links formed to communicate with said tube, a shaft traversing the said tube and bearing openings, and means supporting said shaft on said main frame.

6. I n a truck of theclass described, a main frame, a lifting platform, a rear link assembly for pivotally connecting said main frame and platform comprising a bearing shaft, circular spaced bearings on said platform through which said shaft extends, said bearings being removable from said shaft only by endwise sliding relatively to said shaft, rear links welded at their upper ends to said bearing shaft, a tube welded at its opposite ends to the said links near the lower ends thereof, bearing openings in said links formed to communicate with said tube, and a shaft supported by said main frame traversing the said tube and bearing openings.

7. In a truck of the class described, a main frame, a lifting platform, a'rear link assembly for pivotally connecting said main frame and platform comprising a bearing shaft, circular spaced bearings on said platform through which said shaft extends, rear links secured at their upper ends to said bearing shaft, a tube secured at its opposite ends to the said links near the lower `ends thereof, bearing openings in said links formed to communicate with said tube, and a shaft supported by said main frame traversing the said tube, and bearing openings.

8. In a Ytruck ofthe `class described, a main frame, Ia lifting platform, a rear link assembly for pivotally connecting said main frame and platform comprising a bearing shaft, [circular spaced bearings inse/rtible endwise on said shaft and then secured to said platform, rear links secured at their upper ends to said bearing shaft, bearing openings in said links formed near the lower ends of said links, and a shaft mounted `on said main frame traversing the said bearing openings for supporting said links.

9. In a truck of the class described, a main frame, wheels supporting the rear end of said main frame, a lifting platform, a rear link assembly 4for pivotally connecting said main frame and platform lcomprising a bearing shaft, bearings on said platform with which said shaft cooperates, rear links welded at their upper ends to said bearing shaft, a tube welded at its'opposite ends to the said links near the lower ends thereof, Ibearing openings in said links formed to communicate with said tube, and a shaft on said main frame spaced longitudinally relatively to the axis of rotation `of said wheels and traversing the said bearing openings in said links and said tube, for supporting the said links on said main frame.

10. In a truck of the class described, a main frame, wheels supporting the rear end Iof said main frame, a lifting platform, a rear link assembly for pivotally conecting said main frame and platform 'comprising :a bearing shaft, bearings on said platform with which said shaft cooperates, said bearings being removable from said shaft only by endwise sliding relatively to said shaft, `rear links welded at their upper ends to said bearing shaft, a tube welded at its opposite ends to the said links near the lower ends thereof, bearing openings in said link-s formed to communicate with said tube, and a transverse shaft 'on said main frame spaced longitudinally relatively to the axis of rotation of said wheels, said shaft traversing the said tube and said bearing openings in said link-s for supporting the said links on said main frame.

11. In a truck of the class described, a main frame, Wheels supporting the rear end of said main frame, a lifting platform, a rear link assembly for pivotally `connecting said main frame and platform ycon'iprising a bearing shaft, bearings `on said platform with which said shaft cooperates, rear links welded at their upper ends to said bearing shaft, a tube welded at its opposite ends to the said links near the lower ends thereof, bearing ,openings in said links formed concentric with said tube, a transverse shaft supported on said main frame and spaced longitudinally -relatively to the axis of rotation of said wheels, said shaft traversing the said tube and said bearing openings in said links for supporting the said iinks on said main frame, and means for locking said shaft against rotation relatively to said main frame.

12. In 'a truck of the Iclass described, a main frame, a lifting platform, a rear link assembly for pivotally connecting said main frame and :platform :comprising a bearing shaft, spaced bearings on said lplatform with which the opposite end portions of said shaft cooperate, rear links welded at their upper ends to said bearing shaft and each spaced inwardly relatively to said spaced bearing-s, a tube Welded at its `opposite ends to the said links near the lower ends thereof, bearing openings in said links formed to `coinmunricate with said tube, and a shaft traversing the said tube, said bearing `openings and aligned bearing openings in said :main frame.

13. In a truck lof the class described, a main frame, a lifting platform, a rear link assembly for pivotally connecting said main frame and 

